<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Login Sample</title>
</head>
<body>
    <h1>Login</h1>
    {% with messages = get_flashed_messages() %}
        <div>{{ messages[0] }}</div>
    {% endwith %}
    <form action="{{ url_for('login') }}" method="POST">
        <input type="text" name="userid" id="userid" placeholder="用户ID"></input>
        <input type="password" name="password" id="password" placeholder="密码"></input>
        <input type="submit" name="submit"></input>
    </form>
</body>
</html>